Method and apparatus to reduce vibration

ABSTRACT

Disclosed is an assembly for holding a tool. The assembly may selectively reduce and/or eliminate vibrations received and felt by a user. Reducing vibrations may reduce or eliminate chatter at a working end of a tool.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application is a continuation of U.S. patent application Ser. No.16/276,090 filed on Feb. 14, 2019, which is a continuation of U.S.patent application Ser. No. 14/926,787 filed on Oct. 29, 2015, now U.S.Pat. No. 10,206,691 issued on Feb. 19, 2019. The entire disclosures ofthe above applications are incorporated herein by reference.

FIELD

The subject disclosure relates to reduce an amount of vibration, andparticularly to lessening and minimizing vibrations of a handle due tomovements of a tool bit.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

A procedure may be performed on the subject to assist in removingselected material. In various procedures, such as a surgical procedure,tissues can be removed from a subject, such as excising or resectingtissue. Various tissues can include soft tissues or hard tissues. Duringremoval or extension of a hard tissue, a motorized instrument may beused in the resection and incision of the tissue. During variousprocedures, such as procedures on a vertebra, the instrument may be usedto remove boney tissue from near sensitive areas.

For example, during a spinal procedure, it may be selected to removeboney tissue from near nerves extending from the spinal column of thepatient. The resection of bone tissue may be to assist in relievingpressure on nerves to alleviate pain. Resection, therefore, may be nearsensitive tissue such as nerve bundles, where precise and controlledresection is selected.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

An assembly is disclosed that can couple to and hold a tool. The toolmay be a resection tool, such as a bone resection tool. In variousembodiments the tool can include an elongated shaft having a working endat the end of the shaft. The shaft may be coupled to a motor to providetorque to the tool to rotate the tool during an operation. The operationmay include resecting bone tissue or other tissues from the subject.

The assembly includes an attachment assembly which holds the toolrelative to the motor. The attachment assembly may include an attachmentbase and an attachment tube that can be coupled to a collet. The colletmay include various gears and connection portions that transfer torquefrom the motor to the tool. The attachment may provide various features,such as a bore diameter, length, angle, and the like to allow selectingthe tool to be operated by the motor. Further, the attachment assemblymay include stiffness modification and/or damping features such asdamping members, thicknesses, and the like to minimize and/or reducevibration at a tool tip and caused by the tool felt and received by auser.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a perspective view of an instrument assembly according tovarious embodiments;

FIG. 1A is a perspective view of an angled attachment assembly;

FIG. 2 is a plan view of an attachment assembly, according to variousembodiments;

FIG. 3A is a cross-sectional view of the attachment assembly of FIG. 2taken along line 3A-3A;

FIG. 3B is a cross-sectional view of an alternative attachment assemblyof FIG. 2 taken along line 3A-3A;

FIG. 3C is a cross-sectional view of an alternative attachment assemblyof FIG. 2 taken along line 3A-3A;

FIG. 4 is an exploded view of the attachment assembly of FIG. 3 ;

FIG. 5 is a cross-sectional view of an attachment tube along alongitudinal axis of the attachment tube, according to variousembodiments; and

FIG. 6 is a cross-sectional view of an attachment assembly, according tovarious embodiments. Corresponding reference numerals indicatecorresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

With initial reference to FIGS. 1 and 2 , an instrument assembly 10 isillustrated. The instrument assembly 10 can be similar to an instrumentassembly used to resect tissue, for example the Straightshot^(ø) M4Microdebrider powered handpiece or the Midas Rexø Legend EHS StylusøHigh-Speed Surgical Drill, which may be selectively used forear-nose-throat (ENT) or neurosurgery, sold by Medtronic, Inc. Theinstrument assembly 10 can include a motor housing 16 that extends alonga long axis, and may have various angled or ergonomically shapedportions. The housing 16 may house a motor 17 and have a collet assembly18. The collet 18 can house various portions, such as gears andconnections to a motor within the motor housing 16 with a tool bit 20.The tool bit 20 can include a working end 22 and a shaft 24. The workingend 22 can include a burr, drill bit, resection burr, or otherappropriate working end. Nevertheless, the motor 17 can transfer torqueto the working end 22 through the shaft 24 via an interconnection withinthe collet 18.

The instrument assembly 10 can further include an attachment base 30,also referred to as an attachment housing, and an attachment tube 34.The attachment tube 34 can be interconnected with the attachment base30, as discussed further herein. The attachment tube 34 may form a bore42 and both the attachment tube 34 and the bore 42 may extend from afirst terminal end 35 to a second terminal end 37.

The attachment base 30 and the attachment tube 34 may be operablyremoved from the collet 18 during a selected procedure. For example, theattachment base 30 and the attachment tube 34 may form an attachmentassembly 40 that can include various features, such as a selected sizeof a bore 42 that may extend through at least a portion of theattachment tube 34 and a geometry of the attachment tube 34. Forexample, the attachment tube 34 may be provided as an attachment tube34′, as illustrated in FIG. 1A, where the attachment tube 34 includes afirst tube portion 34 a extending along a first axis A and a second tubeportion 34 b that extends along a second axis B, where the axes A and Bare angled relative to one another. The angle between the axis A andaxis B can be selected based upon a selected procedure and may furtherinclude movable interconnections to provide power to the tool 20 fromthe motor 16 through the angled region. An angle may also be formed byconnecting the attachment tube 34 to an attachment base that has anangle. For example, gears and connections may be provided within theattachment base between a proximal end and the connection end 50. Thus,an angle may be provided between the working end 22 of the tool 20 andthe collet 18 without having the angled tube 34′. Nevertheless, theattachment assembly 40 may be removed from the collet assembly 18 toselectively choose an attachment that may include different featuressuch as the length of the attachment tube 34, angle of the attachmenttube, including the angle of the attachment tube 34′, angle of theattachment base 30, and other features.

The attachment assembly 40 can include an interconnection of theattachment tube 34 with the attachment housing 30. As illustrated inFIG. 3A, the attachment tube 34 may be formed as a separate member fromthe attachment housing 30. The attachment tube 34 may then beselectively coupled to the attachment housing 30 using variousconnection mechanisms.

With continuing reference to FIG. 3A and additional reference to FIGS.3B, 3C, and 4 , the attachment assembly 40 will be discussed in greaterdetail. The attachment assembly 40 includes the attachment tube 34 thatis engaged within the attachment base 30. The attachment tube 34 maygenerally include a cylindrical exterior. Further, the inner bore 42 maybe formed by an internal annular wall. As discussed herein, variousfeatures may be formed into the annular wall to vary a diameter of thebore 42 at selected regions.

The attachment tube 34 may include a connection region 50 that isreceived within an attachment base receiving section 52. The connectionregion 50 may be formed at or near the first terminal end 37. In variousembodiments, the connection region 50 may be formed at the firstterminal end 35 and extend towards the second terminal end 37. The tubeconnection region 50 can extend a length 54 and include an outerdiameter 56. The attachment portion 50 can be received within thereceiving section 52 for coupling of the attachment tube 34 to theattachment base 30.

As discussed herein, the tube connection region 50 may have an externalthread to engage an internal thread in the receiving section 52. It isunderstood, however, that other coupling mechanisms may be provided,such as at least one of a press-fit, a brazing, a welding, a threadedconnection, an adhesive, a stake, or other appropriate connections maybe used to connect the attachment tube 34 to the attachment base 30.Further, the attachment tube 34, in various embodiments, may be coupledboth directly and indirectly to the attachment base 30 (illustrated inFIG. 3A), may be only indirectly coupled to the attachment base 30(illustrated in FIG. 3B), or may be only coupled directly to theattachment base 30 (illustrated in FIG. 3C), as discussed herein.

The attachment section 52 of the attachment base 30 can include a firstinner diameter 58 that may be greater than the outer diameter 56 toreceive an intermediate or damping member 70 (also illustrated in FIG. 4). The receiving section 52 may further include a second inner diameter60 that may be substantially equivalent to or slightly larger than theouter diameter 56 of the tube connection section 50. The relationship ofthe inner diameter 58 and the outer diameter 56 of the damping member 70may allow or form a press-fit connection between the damping member 70and the attachment base 30. When assembled, therefore, the connectionregion 50 of the attachment tube 34 may be generally concentric with theattachment region 52 of the attachment base 30.

The tool 20 may rotate around an axis 20 a. The rotation may be causedby torque being transmitted to the tool 20 from the motor 17 within themotor assembly 16. Chatter may be caused by movement of the tool 20and/or the instrument assembly 10 that is normal to the axis 20 a, suchas in the direction of the double-head arrow 55. It is understood,however, that rotation of the tool 20 may cause vibration in any lateraldirection relative to the axis 20 a. Operating the tool 20 at a selectedrotational speed may also reduce vibrations, such as lateral movementsaway from the axis 20 a by the tool 20 and/or the attachments assembly40.

As illustrated in FIG. 3A, the connection region 50 of the attachmenttube 34 may extend to a direct bonding region 62 to allow for directconnection of the attachment tube 34 to the attachment base 30. Forexample, in the direct bonding region 62, an external thread on the tubeconnection section 50 can engage inner threads that are formed on theinner diameter 60 of the connection region 52 at the direct bondingregion 62. The attachment tube 34 may then be threaded to the attachmentbase 30 to allow for direct connection of the attachment tube 34 to theattachment base 30. It is understood, however, that other connectionsand bonding of the attachment tube 34 to the base 30 can be made. Forexample, selected adhesive materials, press fit, and other connectionscan be formed between the attachment tube 34 and the attachment base 30.

With reference to FIG. 3B, it is understood, that the attachment tube 34need not be directly connected to the attachment base 30. Rather, anattachment assembly 40 x may have an attachment tube 34 x The attachmenttube 34 x may be substantially similar to the attachment tube 34,discussed above. The attachment tube may have the connection portion 50that may only contact the damping member 70 within the attachment base30. Thus, the attachment tube 34 may be interconnected with theattachment base 30 via the damping member 70 and not have a directcontact to the attachment base 30, at least within the connection region52. The attachment tube 34 may, however, contact an external surface 53of the attachment base 30.

As illustrated in FIG. 3C, the attachment tube 34 need only directlycontact and connect to the attachment base 30. Connecting the attachmenttube only directly to the attachment base 34 may be a selectedalternative to including the damping member 70. An attachment assembly40 y may have an attachment tube 34 y. The attachment tube 34 y may besubstantially similar to the attachment tube 34, discussed above. Theattachment tube 34 y may have the connection portion 50 that may onlycontact the attachment base 30, including at the exterior surface 53 andthe direct bonding region 62. Thus, a gap 71 may be formed if theinternal diameter 58 is maintained. It is understood, however, that theconnection region 52 may include only the internal diameter 60 such thatno gap 71 is present.

With continuing reference to FIGS. 1-3C and additional reference to FIG.4 , the damping member 70 may extend a length 72 between an outer ordistal end 74 that may include a lip or edge 76 and a proximal end 78.The damping member 70 may be generally cylindrical and have asubstantially annular wall that forms an external diameter 82 and aninternal diameter 84. The external diameter 82 may be substantiallyequivalent to or slightly smaller than the inner diameter 58 of the baseconnection region 52. Therefore, the damping member 70 may be press fitand held in the connection region 52. It is further understood, however,that the damping member 70 may be bonded to the attachment base 30 withan adhesive, a threaded connection, or other appropriate connection. Theinner diameter 84 may be formed to receive the connection region 50 andmay be substantially equivalent to or equal to the inner diameter 60 ofthe connection region 52.

It is further understood that the damping member 70, according tovarious embodiments, may be molded or formed onto the attachment base30, the attachment tube 34, or both. For example, the damping member 70may be injection molded into the connection 50 of the attachment tube 34or the connection 52 of the attachment base 30. Thus, the connection ofthe damping member 70 may be made relative to the attachment assembly 40in selected manners.

The damping member 70 may further have a thickness (formed by thedifference between the internal diameter 84 and the outer diameter 82),length 72, material, or other features selected based upon operationparameters of the attachment assembly 40. The operational parameters mayinclude a rotational speed of the tool 20, the length of the attachmenttube 34, the angle of the attachment tube 34′, the diameter of the shaft24, etc. Still further, the damping member 70 may be selected of amaterial with a relatively high loss factor (i.e. ability to absorband/or transform kinetic energy to another form of energy), but alsosuitable for a selected procedure. For example, a viscoelastic polymermay provide a selected loss factor while being able to withstandrepeated heat and steam sterilization and/or chemical sterilization foran operative procedure on a human patient. The damping member 70 may,for example, be formed of an elastomer, a silicone rubber, FKM (asdetermined by ASTM D1418) or similar fluoroelastomer, chlorobutylelastomer, or other polymer or elastomer material. One example includesViton^(ø) fluoropolymer elastomer sold by E.I. du Pont de Nemours andCompany or The Chemours Company having a place of business atWilmington, Delaware.

As discussed above, in various embodiments, the tube connection region50 can therefore be fitted within the inner diameter 84 of the dampingmember 70 and placed within the connection region 52 of the attachmentbase 30. According to various embodiments, as discussed above, the tubeconnection region 50 may extend no longer than the length 72 of thedamping member 70. It is understood, however, that the attachment tube34 may connect directly and only to the attachment base 30.

The damping member 70 may include the various characteristics discussedabove to tune the vibration of the instrument assembly 70, such as at aportion held by a user at the base (30) or motor housing (16), andchatter at the tool tip 22. The damping member 70 may be tuned to dampenvibration and/or chatter a selected amount by selecting the thickness,length, material, location, etc. The reduced vibration and chatter mayensure a precise resection or operation of the assembly 10.

Tuning the vibration may occur without or in addition to the dampingmember 70 and characteristics of the damping member 70. For example, theattachment region 50 of the attachment tube 34 may include a selectedwall thickness 90 to assist in reduction of vibration during operationof the tool 20. As illustrated in FIGS. 3A, 3B, and 3C, the tubeconnection region 50 can include the wall thickness 90 that can beselected according to various features and limitations of the system.The thickness 90 of the connection region 50 may be formed by increasingan internal diameter of the connection tube 34 on the selected portionof its length. For example, as illustrated in FIGS. 3A, 3B, and 3C, thethickness 90 is formed by an internal diameter 92 in a first portion ofthe attachment tube while an internal diameter 94 is formed in a secondportion of the attachment tube 34. The attachment tube 34 may includeother internal diameters, such as a terminal internal diameter 95 wherethe tool 20 extends from the attachment tube 34 near the working end 22of the tool 20. It is understood, the attachment tube 34 may be coupledto the attachment base 30 without the damping member 70. The selectedtwo internal diameters 92 and 94 forming the thickness may, therefore,alone provide a vibration reduction feature

Reducing the vibration, therefore, may be created using one or more ofthe selected thickness, axial length of a region with a selectedthickness, damping member, etc. Creating a selected vibration designlimitation, including reducing vibrations with a selected feature, maybe selected by reducing or forming a selected thickness at a selectedlocation. The reduced or formed thickness may be by cutting or formingan internal diameter or cutting into an outer surface of the attachmenttube 34.

As briefly discussed above, during operation, the tool 20 may rotatearound the axis 20 a in selected directions and may oscillate. Duringrotation and oscillation of the tool 20, vibrations may be induced inthe attachment assembly 40. The vibrations may be due to rotation of thetool 20 or operation of a motor in the motor housing or motor assembly16. The vibrations may be reduced by either or both (i.e. combined) thethickness 90 of the attachment tube 34 and the damping member 70. Asnoted above, the reduction in vibration and chatter may be achieved byforming the selected thickness 90 at any appropriate axial positionalalong the attachment tube 34. The tool shaft 24 may ride in one or morebearings 100 that are connected within the internal diameter 94 of theattachment tube 34. Therefore, rotation of the tool 20 may be radiallyguided by the attachment tube 34. This may transmit vibrations to theattachment housing 30, the attachment tube 34, and may be transmitted tomotor 16 or other portion grasped by a user.

The attachment tube 34, therefore, includes the selected thickness 90and may be tuned relative to an operation of the tool 20 and geometriesand configurations of the attachment tube 34 and/or the attachment base30. For example, the internal diameter 94 of the bore 33 extendingthrough the attachment tube, the length of the attachment tube 34, ageometry of the attachment base 30, a geometry of the attachment tube34, such as the angle attachment tube 34′, may all be considered whendetermining the selected thickness 90 of the attachment tube 34.Furthermore, a size, including a thickness, such as the differencebetween the internal diameter 84 and the external diameter 82 of thedamping member 70, may be selected for tuning vibrational reduction ofthe attachment assembly 40 and/or the tool assembly 10. Tuning ofvibration felt by a user, such as a surgeon, and tuning of chatter (i.e.lateral movement of the tool head 22) may be based on various features,as discussed herein. Further, specifics of the features, including size,placement, etc. may be based on specifics of the selected attachmentassembly. As discussed above, various attachment assemblies may beprovided in various configurations such that the specifics of the tuningfeatures may vary amongst the attachment assemblies. Thus, one willunderstand that tuning of, such as selecting an amount of eliminatingvibration and chatter, may vary based on upon several considerations.Moreover, it is understood that an attachment tube 34″, as illustratedin FIG. 5 , may include a selected thickness as a vibration reduction ortuning feature away from the terminal ends, including the first terminalend 35. For example, the attachment tube 34″ may include the internaldiameter substantially along an entire length of the attachment tube34″. However, a vibration reducing or tuning feature 120 may be formedas a notch or a groove within or external to the attachment tube 34 toform at least a region having an internal diameter 122. The internaldiameter 122 provides a selected thickness relative to an externaldiameter of the attachment tube 34″. The vibration reduction feature 120may include a complete annular groove or may include formed struts orconnections therein.

Moreover, the vibration reduction feature 120 may provide a selectedflexibility at a selected position along a length of the attachment tube34″ to assist in mitigating or eliminating a selected vibration duringthe operation of the tool tip 20. For example, the vibration reductionfeature may have a length 120 a. The vibration reduction feature 120 mayhave a first end 120′ spaced a distance 120 b from the terminal end 35and a second end 120″ spaced a distance 120 c from the second terminalend 120 c. The selected lengths of 120 a, 120 b, and 120 c can assist intuning the dampening feature and may be selected based uponcharacteristics of the tube 34″ and or the tool 20 and or the attachmentbase 30. Further, the relationship of the internal diameters 122 and 94may be further selected to tune the dampening amount. The internaldiameters 122 and 94 and sections having them may also be selectivelyplaced along the length of the attachment tubes 34, 34′, and 34″.

As discussed above, the bearing 100 may be positioned within theattachment tube 34″ and operation of the tool 20 rotating around theaxis 20 a may cause vibration in the attachment assembly 40. Thevibration reduction feature 120 including the internal diameter 122relative to the internal diameter 94 of the attachment tube 34″ canprovide a selected reduction of the vibration. The attachment tube 34″can be connected with the attachment base 30 in a manner substantiallysimilar to that illustrated in FIG. 3A 3B or 3C, either directly to theattachment base 30, interconnection through the damping member 70 only,or a combination of interconnection to both a damping member 70 anddirect attachments to the attachment base 30.

Accordingly, it is understood that the attachment tube 34 can be formedto include a vibration reduction or tuning feature such as the feature120, illustrated in FIG. 5 , or a thickness 90 of a wall as illustratedin FIG. 3A, 3B, or 3C, either alone or in combination with a dampingmember 70. The vibration reduction features can assist in tuningvibration, which may include minimizing or eliminating vibration, due tooperation of the instrument assembly 10 to rotate the tool 20 around theaxis 20 a. By reducing the vibration, unselected movements of theinstrument may be reduced and operation of the tool 20 may be smoother.This can allow for substantially precise operation of the tool 20,especially over long periods of time, to allow for speed of an operationand selected outcomes for a patient. Reducing vibration may also reduceuser fatigue.

With reference to FIG. 6 an attachment assembly 240 is illustrated. Theattachment assembly 240 is similar to the attachment assembly 40, asdiscussed above. The attachment assembly 240, illustrated incross-section FIG. 6 , is understood to include the bore which mayinclude the internal diameter 92 and the second and different internaldiameter 94. Further, the attachment assembly 240 may include theattachment base 30, as discussed above, and an attachment tube 234connected to the attachment base 30 in at least one of various manners.The attachment tube 234 may be (1) only connected directly to theattachment base 30, (2) interconnected with a damping member (notillustrated in FIG. 6 ) which is connected to the attachment base 30, or(3) connected to both a damping member and the attachment base 30 (notspecifically illustrated in FIG. 6 ) according to various embodimentsincluding features of those embodiments discussed above. The attachmentassembly 240 can further include the connection portion 52 of theattachment base 30 and the connection portion 50 of the attachment tube234.

The attachment tube 234 may include various interconnected portions,such as a damping member 260 that interconnects a first rigid member 264and a second rigid member 266. The rigid members 264, 266 can includeselected exterior dimensions, including those discussed above, andfurther include the internal diameters 92 and/or 94. Further, thedamping member 260 can also define the internal diameter 94. It isunderstood, however, that the damping member 260 can have a selectedaxial position on the attachment tube 234, mass, length, density,internal diameter, or the like, as discussed above. Further, the dampingmember 260 can be formed of various materials, including those discussedabove.

The attachment tube 234 may be connected to the attachment base 30, asdiscussed above. However, the damping member 260 may be included as afeature of the attachment tube 234 or between a portion of theattachment tube 234 and the attachment base 30. As illustrated in FIG. 6, the attachment base 30 can connect with the first rigid portion 264and the damping member 260 can be positioned between a portion of theattachment tube 234, including the second rigid portion 266, and theattachment base 30. Therefore the damping member 260 is positionedbetween at least a portion of the attachment tube 234 (i.e., the secondrigid member 266) and the attachment base 30. In various configurations,one skilled in the art may consider the first rigid portion 264, whenconnected with the attachment base 30, a portion of the attachment base30. However, it is understood, that another damping member, such as thedamping member 70, may be positioned generally near the connection andareas 50, 52 such as in the gap 71. Therefore, it is further understood,that the attachment assembly 240, according to various embodiments, mayinclude a plurality of damping members. As specifically illustrated inFIG. 6 , the damping member 260 is positioned a distance from the distalend 53 of the attachment base 30 and is completely integrated into theattachment tube 234.

The damping member 260 may be connected to the rigid members 264, 266according to various appropriate bonding techniques. For example, thedamping member 260 may be adhered, welded, directly molded onto therigid members 264, 266, or other appropriate bonding or fixationtechniques. Nevertheless, the damping member 260 may dampen motionbetween the second rigid member 266 and the first rigid member 264 andthe attachment base 30. Therefore, the damping member 260, includingvarious features of the damping member 260, may be used to assist intuning chatter and vibration of an instrument 10, as discussed above.

The vibration reduction features can be tuned individually orcollectively to specific configurations of the tool assembly 10, asnoted above. For example, configurations of the tool assembly mayinclude the size of the bore, length of the attachment tube 34, angle ofthe attachment tube 34, etc. The tuning feature(s) may include selectinga thickness of the thickness 90 of the wall, a length of the regionhaving the thickness 90, an axial position of the wall with thethickness 90, thickness and/or length or axial positioning of thedamping member 70, and/or axial position, length, or relative internaldiameter of the dampening feature 120.

Vibration responses and associated reductions (e.g. by damping orincreases in stiffening or decreases in stiffening) of the tool 20 andattachment assembly 40 can be modeled by one or more Structural Dynamictechniques. The modeling techniques may include modal analysis, harmonicanalysis, or transient dynamic analysis. Also, or alternatively, variousphysical testing techniques may be used to determine the vibrationresponses. These methods may predict the frequencies and displacementsinvolved as appropriate to the technique.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

1-20. (canceled)
 21. An attachment assembly for holding a tool,comprising: an attachment base configured to operably couple to a motorhousing assembly; an attachment tube extending from the attachment baseand including first and second rigid members, the first and second rigidmembers each including an internal diameter defined therein andextending therealong; a damping member positioned between and configuredto operably engage the first and second rigid members along theattachment tube, the damping member defining an internal diameterequivalent to the internal diameter of at least one of the first orsecond rigid members; and one or more bearings disposed within theinternal diameter of at least one of the first or second rigid membersand configured to support a tool shaft for rotation within theattachment tube.
 22. The attachment assembly for holding a toolaccording to claim 21, wherein an axial position of the damping memberalong the attachment tube is selectively adjustable to reduce toolvibration.
 23. The attachment assembly for holding a tool according toclaim 21, wherein at least one of the mass, length, density or materialof the damping member is selectively adjustable to reduce toolvibration.
 24. The attachment assembly for holding a tool according toclaim 21, further comprising a plurality of damping members operablyassociated with the attachment tube and configured to reduce toolvibration.
 25. The attachment assembly for holding a tool according toclaim 24, wherein the attachment tube includes a connection region at aproximal end thereof configured to operably engage a second dampingmember, at least a portion of the connection region and the seconddamping member configured to extend within and operably engage theattachment base.
 26. The attachment assembly for holding a toolaccording to claim 25, wherein the second damping member is annular. 27.The attachment assembly for holding a tool according to claim 21,wherein the damping member is formed from at least one of an elastomermaterial, a silicone rubber, a FKM (as determined by ASTM D1418), afluoroelastomer, or a chlorobutyl elastomer.
 28. The attachment assemblyfor holding a tool according to claim 21, wherein the attachment basedefines an internal peripheral surface and the attachment tube defines acomplementary external peripheral surface configured to operably engagethe attachment tube via at least one of a press-fit connection, brazing,welding, a threaded connection, adhesive, or staking.
 29. An attachmentassembly for holding a tool, comprising: an attachment base configuredto operably couple to a motor housing assembly; an attachment tubeextending from the attachment base including first and second rigidmembers, the first and second rigid members each including an internaldiameter defined therein and extending therealong, the attachment tubeincluding a connection region at a proximal end of the second rigidmember; a first damping member positioned between and configured tooperably engage the first and second rigid members along the attachmenttube, the damping member defining an internal diameter equivalent to aninternal diameter of at least one of the first or second rigid members;and a second damping member operably coupled to the connection region,at least a portion of the connection region and the second dampingmember configured to extend within and operably engage the attachmentbase.
 30. The attachment assembly for holding a tool according to claim29, wherein at least one of the first or second damping members isannular.
 31. The attachment assembly for holding a tool according toclaim 29, wherein at least one of the first or second damping members isformed from an elastomer material, a silicone rubber, a FKM (asdetermined by ASTM D1418), a fluoroelastomer, or a chlorobutylelastomer.